주파수 영역에서 비틀림진동에 의한 저속 2행정 디젤엔진을 갖는 추진축계의 피로강도 해석

Fatigue Strength Analysis of Propulsion Shafting System with Two Stroke Low Speed Diesel Engine by Torsional Vibration in Frequency Domain

Prime movers in most large merchant ships adapt two stroke low speed diesel engine which has higher efficiency, mobility and durability. However, severe torsional vibration in these diesel engines may be induced by higher fluctuation of combustion pressures. Consequently, it may lead sometimes to propulsion shafting failure due to the accumulated fatigue stresses. Shaft fatigue strength analysis had been done traditionally in time domain but this method is complicated and difficult in analysing bi-modal vibration system such as the case of cylinder misfiring condition. In this paper authors introduce an assessment method of fatigue strength estimation for propulsion shafting system with two stroke low speed diesel engine in the frequency domain.